The present invention relates to aminoacrylates and their use for making radiation curable compositions for making low odor and/or low extractable coatings, varnishes, adhesives or inks.
Radiation curable, low viscosity inks and coatings are typically composed of mixtures of acrylated monomers and/or oligomers. However, typically monomers which are used to control viscosity of ink or coating compositions do not react completely during polymerization upon exposure to irradiation (UV or electron beam radiation) and remain as residual components in the dried printing ink or coating films and are subject to migration by absorption as well as surface contact. This migration leads to problems, particularly for printing or coating “odor” or “off-taste” sensitive packaging for package such as containers for food and for such applications which require negligible amounts of extractables from cured printing inks or coatings such as pharmaceutical packaging.
It is known to add to radiation curable compositions comprising monomers or oligomers, amines or acrylated amines (aminoacrylates) that enhance the curing of the monomers and oligomers. EP 280222 teaches the use of addition products of a primary mono-amine with (meth)acrylic esters of polyols to enhance the curing rate, even in the presence of oxygen. U.S. Pat. No. 5,482,649 discloses that the modification of acrylated ethoxylated polyols with amines at low level leads to low viscosity aminoacrylates with high reactivities during radiation curing. EP1147098 discloses a (meth)acrylate compound which is the reaction product of a cyclic secondary amine and a poly(meth)acrylate having at least three (meth)acrylate groups, which is useful for radiation curable coating or ink composition having low viscosity, low volatility, and high cure rate under radiation. EP1147098 more specifically discloses the reaction products of ethoxylated trimethylolpropane triacrylate and propoxylated glycerol triacrylate with morpholine.
However when used in compositions for making coatings, varnishes, adhesives and inks, more particularly for food-packaging applications, most of these known aminoacrylates tend to migrate. There is still a need for radiation curable ink, varnish, adhesive and coating compositions having insignificant odor, off-taste and/or extractable components after curing.
The present invention solves these problems.